Recent Advances in the Discovery of Biomarkers for Canine Osteosarcoma

Body Composition Measurements as Predictive Variables for Outcomes of Canine Appendicular Osteosarcoma Treated With Stereotactic Body Radiation Therapy

Body composition measurements (BCM), obtained via computed tomography (CT), have been used as predictors of survival, tumour recurrence, and post-surgical infections in human oncology. There are no reports on using BCM to predict outcomes of dogs with cancer. Elevated BCM is hypothesised to place extra stress on bones weakened by cancer. Pathologic fracture following stereotactic body radiation therapy for canine appendicular osteosarcoma (OSA) frequently results in limb amputation or euthanasia. Additional tools are needed to better predict the risk of fracture development. Our objectives were to determine if any relationships could be identified between BCM and the occurrence of a pathologic fracture and/or survival time in dogs with naturally occurring OSA. Forty-seven dogs with a confirmed OSA and whole-body CT pre-SBRT were included. Several BCM were evaluated, including abdominal volume, visceral adipose tissue volume, whole-body volume, whole-body adipose tissue volume, normalised cross-sectional area of the epaxial muscles at the mid-body of the 13th thoracic vertebra, and attenuations of adipose tissue and epaxial muscles. No BCMs were correlated with survival time. The volume of the entire body (cm3) was significantly positively associated with development of a fracture. No other BCM were correlated with the development of a fracture. The volume of the abdomen (cm3) among our patient subset was positively correlated with the volume of the entire body, and the volume of visceral adipose tissue (cm3) was positively correlated with the total body volume of adipose tissue (cm3). Additional research is needed to verify whether these findings are replicable in larger sample sizes and in prospective settings.

Plasma microRNA signatures predict prognosis in canine osteosarcoma patients

Appendicular central osteosarcoma (OSA) is a common and highly aggressive tumour in dogs. Metastatic disease to the lungs is common and even with chemotherapy the prognosis is generally poor. However, few cases survive well beyond reported median survival times. Current methods, including histologic grading schemes, have fallen short in their ability to predict clinical outcome. MicroRNAs (miRNAs) are small molecules present in all tissues and bodily fluids and are dysregulated in cancer. Previous studies have demonstrated the diagnostic and prognostic potential of miRNAs in canine OSA. We sought to investigate multiple miRNA and multiple variable models for diagnosis and prognosis of canine OSA using plasma samples across three populations of dogs from two veterinary biobanks. Fifty-six miRNAs were analyzed by real-time quantitative polymerase chain reaction. MiR-214-3p was the only miRNA with increased expression across all OSA populations compared to controls. Using a decision tree model for diagnosis, miR-214-3p was the first step in this multi-miRNA model. High expression of miR-214-3p alone was also a predictor of shorter overall survival and disease-free interval across all populations. In both multiple miRNA and multiple variable models, miR-214-3p was always the first decision point with high expression consistently predicting a worse prognosis. Additional miRNAs in combination with low expression of miR-214-3p similarly had a worse prognosis demonstrating better outcome prediction using multiple miRNAs compared to using miR-214-3p alone. Multiple variable models only need to use miRNAs to be predictive although clinical parameters such as age, sex, and tumour location were considered. MiR-214-3p is clearly an important prognostic predictor of canine OSA in plasma as supported by previous studies and across our multiple sample populations. Multiple miRNA models provided superior categorization of patients in predicting clinical outcome parameters compared to the single miRNAs.

Influence of Metamizole on Antitumour Activity of Risedronate Sodium in In Vitro Studies on Canine (D-17) and Human (U-2 OS) Osteosarcoma Cell Lines

The availability of metamizole varies greatly around the world. There are countries such as the USA, UK, or Australia where the use of metamizole is completely forbidden, and there are also countries where this drug is available only on prescription (e.g., Greece, Italy, Spain, etc.) and those in which it is sold OTC-over the counter (e.g., most Asian and South American countries). Metamizole, as a drug with a strong analgesic effect, is used as an alternative to other non-steroidal anti-inflammatory drugs, alone or in combination with opioid drugs. Risedronate sodium is a third-generation bisphosphonate commonly used in orthopaedic and metabolic diseases of the musculoskeletal system, including hypercalcemia, postmenopausal osteoporosis, Paget's disease, etc. The aim of this study was to check whether there were any pharmacological interactions between metamizole and risedronate sodium in in vitro studies. Cell viability was assessed using the MTT method, the number of apoptotic cells was assessed using the labelling TUNEL method, and the cell cycle assessment was performed with a flow cytometer and propidium iodide. This was a pilot study, which is why only two cancer cell lines were tested: D-17 of canine osteosarcoma and U-2 OS of human osteosarcoma. Exposure of the canine osteosarcoma cell line to a combination of risedronate sodium (100 µg/mL) and metamizole (50, 5, and 0.5 µg/mL) resulted in the complete abolition of the cytoprotective activity of metamizole. In the human osteosarcoma cell line, the cytotoxic effect of risedronate sodium was entirely eliminated in the presence of 50 µg/mL of metamizole. The cytoprotective and anti-apoptotic effect of metamizole in combination with risedronate sodium in the tested human and canine osteosarcoma cell lines indicates an urgent need for further in vivo studies to confirm or disprove the potential dose-dependent undesirable effect of such a therapy.

Investigating cell death responses associated with histotripsy ablation of canine osteosarcoma

BACKGROUND

Osteosarcoma (OS) is the most frequently occurring primary bone tumor in dogs and people and innovative treatment options are profoundly needed. Histotripsy is an emerging tumor ablation modality, and it is essential for the clinical translation of histotripsy to gain knowledge about the outcome of nonablated tumor cells that could remain postablation. The objective of this study was to characterize the cell death genetic signature and proliferation response of canine OS cells post a near complete histotripsy ablation (96% ± 1.5) and to evaluate genetic cell death signatures associated with histotripsy ablation and OS in vivo.

METHODS

In the current study, we ablated three canine OS cell lines with a histotripsy dose that resulted in near complete ablation to allow for a viable tumor cell population for downstream analyses. To assess the in vivo cell death genetic signature, we characterized cell death genetic signature in histotripsy-ablated canine OS tumors collected 24-h postablation.

RESULTS

Differential gene expression changes observed in the 4% viable D17 and D418 cells, and histotripsy-ablated OS tumor samples, but not in Abrams cells, were associated with immunogenic cell death (ICD). The 4% viable OS cells demonstrated significantly reduced proliferation, compared to control OS cells, in vitro.

CONCLUSION

Histotripsy ablation of OS cell lines leads to direct and potentially indirect cell death as evident by, reduced proliferation in remaining viable OS cells and cell death genetic signatures suggestive of ICD both in vitro and in vivo.

Applicability of thermography for cancer diagnosis in small animals

Medical thermography is an imaging test used to monitor skin surface temperature. Although it is not a recent technique, significant advances have been made since the 2000s with the equipment modernization, leading to its popularization. In cancer diagnosis, the application of thermography is supported by the difference in thermal distribution between neoplastic processes and adjacent healthy tissue. The mechanisms involved in heat production by cancer cells include neoangiogenesis, increased metabolic rate, vasodilation, and the release of nitric oxide and pro-inflammatory substances. Currently, thermography has been widely studied in humans as a screening tool for skin and breast cancer, with positive results. In veterinary medicine, the technique has shown promise and has been described for skin and soft tissue tumors in felines, mammary gland tumors, osteosarcoma, mast cell tumors, and perianal tumors in dogs. This review discusses the fundamentals of the technique, monitoring conditions, and the role of thermography as a complementary diagnostic tool for cancer in veterinary medicine, as well as future perspectives for improvement.

Generating Detailed Spectral Libraries for Canine Proteomes Obtained from Serum and Urine

Domestic dogs (Canis lupus familiaris) are popular companion animals. Increase in medical expenses associated with them and demand for extending their lifespan in a healthy manner has created the need to develop new diagnostic technology. Companion dogs also serve as important animal models for non-clinical research as they can provide various biological phenotypes. Proteomics have been increasingly used on dogs and humans to identify novel biomarkers of various diseases. Despite the growing applications of proteomics in liquid biopsy in veterinary medicine, no publicly available spectral assay libraries have been created for the proteome of canine serum and urine. In this study, we generated spectral assay libraries for the two-representative liquid-biopsy samples using mid-pH fractionation that allows in-depth understanding of proteome coverage. The resultant canine serum and urine spectral assay libraries include 1,132 and 4,749 protein groups and 5,483 and 25,228 peptides, respectively. We built these complimentary accessible resources for proteomic biomarker discovery studies through ProteomeXchange with the identifier PXD034770.

Characterizing the Ablative Effects of Histotripsy for Osteosarcoma: In Vivo Study in Dogs

Osteosarcoma (OS) is a malignant bone tumor treated by limb amputation or limb salvage surgeries and chemotherapy. Histotripsy is a non-thermal, non-invasive focused ultrasound therapy using controlled acoustic cavitation to mechanically disintegrate tissue. Recent ex vivo and in vivo pilot studies have demonstrated the ability of histotripsy for ablating OS but were limited in scope. This study expands on these initial findings to more fully characterize the effects of histotripsy for bone tumors, particularly in tumors with different compositions. A prototype 500 kHz histotripsy system was used to treat ten dogs with suspected OS at an intermediate treatment dose of 1000 pulses per location. One day after histotripsy, treated tumors were resected via limb amputation, and radiologic and histopathologic analyses were conducted to determine the effects of histotripsy for each patient. The results of this study demonstrated that histotripsy ablation is safe and feasible in canine patients with spontaneous OS, while offering new insights into the characteristics of the achieved ablation zone. More extensive tissue destruction was observed after histotripsy compared to that in previous reports, and radiographic changes in tumor size and contrast uptake following histotripsy were reported for the first time. Overall, this study significantly expands our understanding of histotripsy bone tumor ablation and informs future studies for this application.

Cryopreservation does not change the performance and characteristics of allogenic mesenchymal stem cells highly over-expressing a cytoplasmic therapeutic transgene for cancer treatment

Background

Mesenchymal stem cells (MSCs) driven gene directed enzyme prodrug therapy is a promising approach to deliver therapeutic agents to target heterogenous solid tumours. To democratize such a therapy, cryopreservation along with cold chain transportation is an essential part of the logistical process and supply chain. Previously, we have successfully engineered MSCs by a non-viral DNA transfection approach for prolonged and exceptionally high expression of the fused transgene cytosine deaminase, uracil phosphoribosyl transferase and green fluorescent protein (CD::UPRT::GFP). The aim of this study was to determine the effects of cryopreservation of MSCs engineered to highly overexpress this cytoplasmic therapeutic transgene.

Methods

Modified MSCs were preserved in a commercially available, GMP-grade cryopreservative—CryoStor10 (CS10) for up to 11 months. Performance of frozen-modified MSCs was compared to freshly modified equivalents in vitro. Cancer killing potency was evaluated using four different cancer cell lines. Migratory potential was assessed using matrigel invasion assay and flow cytometric analysis for CXCR4 expression. Frozen-modified MSC was used to treat canine patients via intra-tumoral injections, or by intravenous infusion followed by a daily dose of 5-flucytosine (5FC).

Results

We found that cryopreservation did not affect the transgene expression, cell viability, adhesion, phenotypic profile, and migration of gene modified canine adipose tissue derived MSCs. In the presence of 5FC, the thawed and freshly modified MSCs showed comparable cytotoxicity towards one canine and three human cancer cell lines in vitro. These cryopreserved cells were stored for about a year and then used to treat no-option-left canine patients with two different types of cancers and notably, the patients showed progression-free interval of more than 20 months, evidence of the effectiveness in treating spontaneously occurring cancers.

Conclusion

This study supports the use of cryopreserved, off-the-shelf transiently transfected MSCs for cancer treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03198-z.

Histotripsy Ablation of Spontaneously Occurring Canine Bone Tumors In Vivo

OBJECTIVE

Osteosarcoma (OS) is a devastating primary bone tumor in dogs and humans with limited non-surgical treatment options. As the first completely non-invasive and non-thermal ablation technique, histotripsy has the potential to significantly improve the standard of care for patients with primary bone tumors.

INTRODUCTION

Standard of care treatment for primary appendicular OS involves surgical resection via either limb amputation or limb-salvage surgery for suitable candidates. Biological similarities between canine and human OS make the dog an informative comparative oncology research model to advance treatment options for primary OS. Evaluating histotripsy for ablating spontaneous canine primary OS will build a foundation upon which histotripsy can be translated clinically into a standard of care therapy for canine and human OS.

METHODS

Five dogs with suspected spontaneous OS were treated with a 500 kHz histotripsy system guided by real-time ultrasound image guidance. Spherical ablation volumes within each tumor (1.25-3 cm in diameter) were treated with single cycle histotripsy pulses applied at a pulse repetition frequency of 500 Hz and a dose of 500 pulses/point.

RESULTS

Tumor ablation was successfully identified grossly and histologically within the targeted treatment regions of all subjects. Histotripsy treatments were well-tolerated amongst all patients with no significant clinical adverse effects. Conclusion & Significance: Histotripsy safely and effectively ablated the targeted treatment volumes in all subjects, demonstrating its potential to serve as a non-invasive treatment modality for primary bone tumors.

Doxorubicin-Loaded Lipid Nanoparticles Coated with Calcium Phosphate as a Potential Tool in Human and Canine Osteosarcoma Therapy

Osteosarcoma (OSA) is the most frequently diagnosed primary malignant bone tumor in humans and dogs. In both species, standard chemotherapy can be limited by multidrug resistance of neoplastic cells, which prevents intracellular accumulation of cytotoxic drugs, resulting in chemotherapy failure. In this study, a lipophilic ester of doxorubicin (C12DOXO) was loaded into nanoparticles (NPs) using the “cold microemulsion dilution” method. The resulting NPs were then coated with calcium phosphate (CaP) in two different ways to have calcium or phosphate ions externally exposed on the surface. These systems were characterized by determining mean diameter, zeta potential, and drug entrapment efficiency; afterward, they were tested on human and canine OSA cells to study the role that the coating might play in increasing both drug uptake into tumor cells and cytotoxicity. Mean diameter of the developed NPs was in the 200–300 nm range, zeta potential depended on the coating type, and C12DOXO entrapment efficiency was in the 60–75% range. Results of studies on human and canine OSA cells were very similar and showed an increase in drug uptake and cytotoxicity for CaP-coated NPs, especially when calcium ions were externally exposed. Therefore, applications in both human and veterinary medicine can be planned in the near future.

Proteomic Assessment of Extracellular Vesicles from Canine Tissue Explants as a Pipeline to Identify Molecular Targets in Osteosarcoma: PSMD14/Rpn11 as a Proof of Principle

Osteosarcoma (OS) is a highly malignant bone tumour that has seen little improvement in treatment modalities in the past 30 years. Understanding what molecules contribute to OS biology could aid in the discovery of novel therapies. Extracellular vesicles (EVs) serve as a mode of cell-to-cell communication and have the potential to uncover novel protein signatures. In our research, we developed a novel pipeline to isolate, characterize, and profile EVs from normal bone and osteosarcoma tissue explants from canine OS patients. Proteomic analysis of vesicle preparations revealed a protein signature related to protein metabolism. One molecule of interest, PSMD14/Rpn11, was explored further given its prognostic potential in human and canine OS, and its targetability with the drug capzimin. In vitro experiments demonstrated that capzimin induces apoptosis and reduces clonogenic survival, proliferation, and migration in two metastatic canine OS cell lines. Capzimin also reduces the viability of metastatic human OS cells cultured under 3D conditions that mimic the growth of OS cells at secondary sites. This unique pipeline can improve our understanding of OS biology and identify new prognostic markers and molecular targets for both canine and human OS patients.